Process op improving haib



UNITED STATES PATENT OFFICE- ALBERT 0. TROSTEL, 0Z5 MILWAUKEE, WISCO NSIN.

PROCESS OF IMPROVING HAIR, WOOL, AND FURS.

No Drawing.

in a more valuable way of hair of various kinds which has heretofore been either a waste product or a product of comparatively small value, notably hair removed from hides in tanning; the hair removed from animals in clipping; the hair cut from human heads, etc.; to provide a process whereby extremel coarse hair-like wools (often termed-cul wools) may be improved by rendering them more pliable, shrinkable and spinnable; to provide a process which effects the desired results without mutilating the structure of the hair or wool treated, and without impairing its luster, while very pronouncedly enhancing its spinning and feltmg characteristics. Expressed in another way, the general object of the invention is to convert hair or coarse wool, which is naturally of a more or less bristle-like character, into a condition in which it greatly resembles good or high grade wool in its softness, spinning and felting qualities, so that it may be used in lieu of wool or in a mixture with wool or other materials capable of being spun, woven, felted, or knitted. My invention is also designed to improve the felting characteristics of wool generally. The invention conslsts in the matters hereinafter described and more particularly pointed out in the append ed claims.

It has been more or less generally understood and believed that the felting characteristic of wool was largely due to surface conditions, e. g. scalular covering either in its natural state or artificial roughenings of the surface, produced by etching, splitting, warping, etc., and accordingly it was believed that those kinds of hair and wool which are more or less devoid of surface roughenings were correspondingly defective in felting and spinning qualities.

Specification of Letters Patent. Patented Ma 15 1921.

Application filed December 12, 1919. Serial No. 344,417.

I have discovered, however, that hair which appears under the microscope to be practically or absolutely devoid of exposed scalular projections can be made to felt, and that wool can be given increased felting propertles, apart from and not dependent upon the surface imbri'cations thereof.

I have discovered that felting, spinning, and weav ng characteristics can be created 1n hair, etc., and can be increased in wool by making the hair or wool porous. This porosity results in voids which can be closed upby the application of heat to my prepared hair or wool, resulting in shrinking or feltin in situ. At the same time I am enable to do this without injuring the true hair fiber.

I am aware that others have attempted to lmpart felting characteristics to hair by the action of alkalis and acids, but all of them so far as I am aware, have been unsuccessful becausethey have used too drastic reagents, resultmg in a splitting, etching, etc., of the hair itself and injury of the hair fiber. They have not freed the hair from undesirable byproducts formed as a result of their reagents, such as sodium carbonate, lime soap, etc., the presence of which renders the hair stiff and harsh and prevents that complete feltmg or shrinking which my process is designed to and does effect. The other workers in this art have also failed to discover a very important and essential element in the treatment, which is ane'ntire freedom from exposure to high temperature during the process. If the temperature be allowed to rise during any of the treatment the fiber will commence to shrink, with the result that the finished part of its most characteristic.

I have discovered that by using weak alkaline solutions, preferably one of limited solubility and self-replenishing, I can remove roduct has lost a large esirable and sought for substantial percentages of the oleaginous retains its original gloss and luster unimpaired, and indeed, the gloss and luster are generally improved by the treatment; examination of the hair which has been treated, under a high power microscope, discloses no pitting or mutilation of the hair and very little or no change in the surface appearance of the hair, although the hair as a whole may appear more translucent or more nearly transparent than before treatment. There is no perceptible greater exposure of the scalular integument than before the treatment; that is, the hair surface is not roughened or made more uneven.

Describing a preferred and, in accordance with my present knowledge, the best method or process of carrying out my invention, I proceed substantially as follows:

Assuming the treatment of natural hair, for example cows hair, and assuming that the hair is clean, I first subject the hair to treatment in a weak alkaline bath,preferably in a bath of weak milk of lime, preferably sharpened somewhat by addition of a small percentage of sulfid of sodium-sa one-fifthof one per cent. of the weight of the bath solution. Milk of lime at low temperatures (32 F. to 68 F.) contains about 0.13 per cent of CaO in solution. \Vith the addition of the stated amount of alkali sulfid, 0.2 per cent, the total dissolved alkalinity of the bath is less than 0.5 per cent. hair is soaked in this solution for a considerable period of time, say from ten days to two Weeks. This alkaline treatment results in the solution and removal of various extractive matters from the interior of the ability will not be obtained. Any heating during the process will shrink the hair and concomitantly lessen its value for my purposes.

The next step of my process is to free the hair from the lime soap, the carbonate of lime, and any loosened animal matter.

Preferably, I first wash the hair thoroughly in water after it has been removed from the lime bath, but this step is not essential, since the subsequent chemical treatment will re move the impurities, which will be Washed out.

The hair, either Washed or unwashed, is next subjected to treatment in a bath of di- The lute acid. Preferably, and in accordance with my best results, I use dilute muriatic or hydrochloric acid. I prefer to use a bath of a strength which will insure a residual one per cent. of actual acid in the bath after the alkaline content of the hair has been fully neutralized. A somewhat smaller percentage of acid will produce the necessary results. but in order 'to avoid all possibility of anthrax infection, I use the acid of about the strength specified. The wool or hair is subjected to the acid treatment for a period of approximately twenty-four hours, and it may be noted in this connection that the treatment may be somewhat shorter and still secure good results, but that this stated time is preferred in order to insure sterilization as regards anthrax germs.

Following the acid treatment, the hair is washed out thoroughly in cold water and in such manner as to insure the elimination of the acid.

The product is next dried, preferably at room temperature or at a very slightly :increased temperature. Vacuum or suction may be used to hasten drying and prevent heating. Great care must be taken to avoid any substantial heating during drying or the described prior treatment as the product is extremely susceptible to shrinking or felting in the presence of heat, and to insure its retaining its full felting or matting qualities slow cold drying is essential.

The product is afterward carded and, if necessary or preferred, tempered and otherwise treated in practically the same Way as ordinary wools, and is in fact remarkably like wool in its characteristics upon the completion of the process.

In case wool is used because of the greater amount of oleaginous material present, running as high as 25 to 40 per cent. in some cases, it may be advisable to first degrease the 'wool in any of the Well known manners, but of course in the absence of heat.

Chemical tests have proved that substantial percentages of the oleaginous, nitrogenous, and sulfur constituents of the hair are removed by the process. A series of most carefully conducted microscopical examinations by experts in the use of the microscope has failed to disclose any perceptible mutilation or destruction of the hair surface structure. I deduce and believe, therefore, that the process results in remov ing intercellular matter, resulting in a largely increased porosity, and this theory is strengthened, as I view the matter, by the marked increase in pliability or softness, by the increased shrinking and felting qualities, and by the greater absorptive and more readily permeable qualities of the product, as regards liquids.

It will, of course, be understood that my process may be varied without departing from the invention, and accordingly I have claimed both the process and the product by claims of varying scope.

' As a result of the cold extraction, cold souring, and cold drying the hair loses substantially in wei ht but not in apparent volume and is left in what may be called an unstable physical condition. On heating it shrinks and condenses, taking permanently whatever new form may have been given it by spinning, weaving, felting or the like and becomes stable in its new form, all stresses and strains produced by the working in the resilient or springy original extracted hair being relieved. In the heated and shrunk fabric, each individual fiber has a permanent form conditioned by the form of the neighboring fibers; and the fabric is therefore strong and durable. Evenround smooth hair treated by the present process will give an ultimate felted fabric much like broadcloth made from good quality wool.

After the drying and prior to the shrinking, the hair or fiber may be advantageously given a treatment with various mineralizing materials, such as chrome salts, to enhance its resistance to heat, organisms, vermin, etc., but this matter I do not herein claim, it forming subject-matter of my copending application, Serial No. 341,695.

claim as my invention:

1. As a new textile material, altered hairy material having a surface gloss, smoothness and other characteristics of unaltered original material and having substantially the same apparent volume, but distinguished therefrom by possessing a porous texture .and by the property of shrinking and becoming dense under the influence of heat, said textile material possessing the characteristics of hairy material exposed to a prolonged cold treatment With weak alkaline solution followed by a removal of alkali and dried at a low temperature.

2. As anew textile material, altered bovine hair having the surface gloss, smoothness and other characteristics of unaltered original bovine hair and having substantially the same apparent volume, but distinguished therefrom by possessing a porous texture and by the property of shrinking and becoming dense under the influence of heat, said textile material possessing the characteristics of hairy material exposed to a prolonged cold treatment with weak alkaline solution followed by a removal of alkali and dried at a low temperature.

' 3. As anew textile material, hairy material retaining its exterior surface and gloss unimpaired and retaining its original shape and apparent volume but rendered porous ing fibers susceptible of shrinkage by heat,

which comprises exposing such a material to the action of a weak alkaline bath in the cold for a number of days and until the individual fibers acquire a substantial degree of porosity but without corrosion or. etching to any substantial degree or the fiber diminishing substantially in apparent volume, removing the alkali in the cold and drying at a temperature insufiiclent to cause any substantial shrinkage or condensation of the porous product made in the first operation.

5. The process of enhancing the textile qualities of hair and the like and producing fibers susceptible of shrinkage by heat, which comprises exposing such a material to the action ofa weak alkaline bath in the cold, the dissolved alkaline materials in said bath not exceeding 0.5 per cent, said exposure being for a number of days and until' the individual fi ers acquire asubstantial degree of porosity but without corrosion or etching to any substantial degree or the fiber diminishing substantially in apparent volume, removing the alkali in the-cold and drying at a temperature insufficient to cause any substantial shrinkage or condensation of the porous product made in the first operation.

6. The process of enhancing thew-textile qualities of hair and the like and producing fibers susceptible to shrinkage by heat, which comprises exposing such a material to the action of a bath comprising milk of lime and about 0.2 per cent. of an alkali sulfid, said exposure being for a number of days and until the individual fibers acquire a substantial degree of porosity but without corrosion or etching to any substantial degree or the fiber diminishing substantially 1n apparent volume, removing the ALBERT O. TROSTEL.

Witnesses:

ALBERT G. MANNs, IRMA FELDMANN. 

